This invention relates generally to cleaning devices. More specifically, the present invention relates to an improved cleaning head assembly for a vacuum cleaning apparatus of the wet, dry and wet/dry types.
Many prior devices for cleaning rugs, carpets and the like have consisted basically of a system for delivering cleaning solution (usually a hot aqueous detergent solution) to the rug or carpet, and a system for vacuuming the applied cleaning solution from the rug or carpet. Many such "vacuum cleaners" or carpet cleaning machines have been provided with a rotatable brush which is intended to contact and brush the and debris so that it can be sucked up into a collection tank or bag by a vacuum motor. The brush is able to perform its intended purpose only to the extent the distal ends of the bristles of the brush are in contact with the surface being cleaned. Keeping the brush in contact is not a problem provided the surface being cleaned is absolutely uniform, smooth and level. However, in many cases, the surface is irregular or bumpy. When this irregular surface condition exists, the efficiency of the brush is diminished, since only some of the bristles can contact the surface being cleaned. One of the best devices for maintaining contact between the brush and the surfaces being cleaned where the surface is irregular is shown in U.S. Pat. No. 4,976,003, entitled CLEANING APPARATUS, and issued to one of the inventors herein.
A typical vacuum system for a carpet cleaning device generally comprises a vacuum chamber or nozzle disposed in a cleaning head assembly which is positioned over the rug, carpet or the like to "suck up" applied cleaning solution, dirt and other debris, and a vacuum pump in fluid communication with the cleaning head assembly to generate a partial vacuum therein. There are two variations of the basic system found in the marketplace. In one embodiment, the cleaning head, the solution delivery system, the vacuum system, and one or more solution tanks are integrated into a single wheeled housing which is pulled over the rug or carpet by the operator. In the other embodiment, the cleaning head is a separate unit from a wheeled housing containing the vacuum system, the solution delivery system and the solution tanks. Both embodiments have advantages and disadvantages. For example, the cleaning unit having a separate cleaning head is easier to manipulate over a rug or carpet surface, but because of the additional distance the fresh solution must be pumped to the cleaning head and the spent solution must be transferred back to the housing after the aspiration thereof from the rug or carpet, the power requirements for both the solution pump and the vacuum pump are substantially increased. Moreover, the connections for the tubings for the separate cleaning head present maintenance problems because they frequently leak solution.
The cleaning devices which are completely contained within a wheeled housing are most desirable from a manufacturing and maintenance point of view, but they are more difficult to move over a rug or carpet surface during the cleaning operation, especially where space is limited, for example in small offices or narrow hallways. As a result, their use has been limited to professional or commercial rug and carpet cleaners. Moreover, they tend to be larger and heavier than non-industrial units.
Accordingly, there has been a need for a novel vacuum cleaning apparatus of the wet, dry and wet/dry types having a proven, durable construction, which can be easily maneuvered over a surface to be cleaned during the cleaning operation, and is constructed in a manner improving the utility of the vacuum cleaning apparatus over prior devices. In this regard, it is noted that prior industrial vacuum cleaning devices formed as an integral unit have been designed wherein they must be pulled by the operator to ensure that dirt and debris loosened from the surface to be cleaned by the cleaning brush is sucked up into the vacuum chamber. This required the cleaning apparatus to be turned 180.degree. every time an opposite wall was encountered in order to ensure adequate cleaning coverage. There therefore exists a need for a novel cleaning head assembly for use in a vacuum cleaning apparatus which permits the apparatus to be either pushed or pulled and yet provide means for adequately sucking up debris loosened by the cleaning brush without reducing the vacuum drawn through the cleaning head. Additionally, an improved cleaning head assembly is needed which assists in propulsion of the cleaning apparatus across the surface to be cleaned, in both the push and pull directions. The present invention fulfills these needs and provides other related advantages.